Self-feeding carburetor



Jan. 3, 1928. 1,654,604

, E. A. ROCKWELL SELF FEEDING CARBURETOR File Aug. 1925 2 Sheets-Sheet 1 awueutoz Jan. 3, 1928.

E. A. ROCKWELL SELF FEEDING CARBURE'I'OR Filed Aug. 2. 1925 ZSheets-Sheet 2 Patented Jan. 3, 1928. I

UNITED STATES PATENT OFFICE.

EDWARD A. ROCKWELL, OF FOREST HILLS, NEW YORK, ASSIGNOR TO STEWART- WARNER SPEEDOMETER CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF VIRGINIA.

SELF-FEEDING CARBURETOR.

Application filed. August 2, 1923. Serial No. 655,235.

My invention relates to carburetors and fuel feeding means provided in connectlon therewith by means of which the carburetor will receive its supply of fuel without requiring' a high degree of vacuum or other elevating agency and by means of which the fuel is conveyed in atomized ,COIldltlOl] therefrom to the point at which it. is to be admitted to the engine.

The purpose of this invention is to provide an improved fuel mixture forming and conducting apparatus for supplying fuel to an internal combustion engine, particularly adapted for serving the engine of a motor vehicle. It consists in the elements and features of construction shown and described, as indicated in the claims.

While my invention is capable of being embodied in many difi'erent forms for the purpose of illustration I have shown certain forms of the same in the accompanying drawings in which Figure 1 is a vertical elevation of an apparatus made in accordance with my invention shown partly in section;

Figure 2 is an enlarged vertical section of the controlling devices used in the apparatus; r

Figure 3 is a vertical section of the carburetor-.-proper, and

Figure 4 is a vertical section of a modified form of my apparatus.

In the drawings I have shown an automobile engine 1 of any desired character ha 'ing a manifold 2 adapted to be supplied with gasolene from a reservoir 3 having the usual vented filling cap 4. Atube 5 leads from the reservoir 3 preferably out through the top of the same although ittis to be understood that, if desired, the pipe 5 ma be connected to the bottom of the reservoir 3 x as shown in dotted lines inFigure 1. The

14 is arranged to be vertically movable within the valve seat member 13 and is actuated by a float 15 carried by a pivoted arm 16 rotatably supported in an extension 17 on the lower side of the cover plate '10. The cover plate which is secured by screws 19 to a carburetor housing 20, has an air inlet into the housing, 20, through a boss, 18. The air- 'commi'ngles with the liquid fuel received from the jet nozzle 25 and passes through a Venturi passageway 26 thus providing a gaseous fuel mixture which passes upwardly through a tube 27 that is connected to the interior sleeve 23 by any suitable type of coupling 28. The gaseous fuel mixture proceeds upwardly through the tube 27 until it reaches a discharge nozzle 29 located within a member having a Venturi passageway 30 in an air intake housing 31, the flow through which is controlled by a throttle valve 32 in the usual-way. The air inlet 18 is connected by a tube 33, which is secured thereto by a coupling 34, to a tubular projection 35 on the air intake housing 31 by means of a coupling 36. The interior of the tubular projection 35 communicates with a chamber 37 in another tubular projection 38 having an adjustable hollow screw-threaded valve seat member 39 screw-threaded into the same. Through the middle of the valve seat member 39 there is provided a port 40 for admitting air and the outside of the member 39 is corrugated to receive a spring arm 41 which is secured by screws 42 to the side of the tubular member 38. The adjustment of the member 39 adjuststhe amount of airadmitted through the passageway 40 and past a valve 43 which is received in the passageway 40. It will be noted that the valve 43 is tapered at its lower end and that the shape and size of the surfaces contained upon the tapered end of this valve may be chosen as desired to agree with the particular metering and is provided with a piston 49 within a dash-pot 50 screw-threaded into the air intake housing 31 and provided with a corrugated surface 51 to' cooperate with a spring arm 51 secured by a screw 51 to the housing 31. The spring 47 tends to keep the valve 44 closed during certain periods of the operation of the apparatus. The gaseous mixture obtained in this way passes thence to the manifold 2 of the engine.

The modification of my invention as shown in Figure 4 is constructed in the same manner as the form previously described except instead of the adjustable screw-threaded valve seat 39 there is provided a vertically movable sleeve 51 within the tubular extension 38, said sleeve 51 having a number of air ports 52 therein and being connected at its lower end by means of a steel wire 53 to a corrugated adjusting rod 54 having a handle 55 located on a dash 56. A flexible housing 57 is provided around the wire 53 and is connected at its inner-end to a screw-threaded sleeve 58 se cured to the outside of the tubular extension 38 and having a split end with wings 59 adapted to act as a clamp around the said inner-end of the flexible housing 57 with the aid of a scew 60.

In the operation of my invention, it being understood that the reservoir 3 has therein -a supply of gasoline, the gasoline will flow therefrom through the pipe 5 to the carburetor housing 20 either under the influence of the vacuum, which for this purpose need be only a very low vacuum, or by gravity alone in case the supply pipe from the reservoir is aslocated in dotted lines in'Figure 1. The gasolene will thus be maintained in the carburetor housing 20 at a given level owing to the presence of the float 15 which' controls the opening of the valve 14. The valve 33 will at all times be slightly open thus permitting the inflowof air through the passageway 40 and thence through the tube 33 and inlet 18 to the interior of the housing 20. The air will thence flow through the ports 21 and between the sleeves 22 and 23 \and thereafter upwardly around the nozzle 25, thus communicating with the, liquid therein so as to cause the vaporization of the same and. in this way providing a gaseous mixture of air and gasolene vapor which pass upwardly through the tube 27 to the nozzle 29 and thence through the venturi 30. Under ordinary conditions of operation this gaseous mixture will be the required mixture for operating the engine 1 but when the engine is speeded up or when under a heavy load, the throttle 32 has been opened to a large degree the result will be to produce a greater difi'erential bet-ween the pressure below and above the valve 44, thus unseating the same. As a result the valve 43 will become unseated to a greater degree thus admitting an increased flow of air to the jet nozzle 25 and providing in this way an increase-in the supply of fuel. At the same time there will be, as a result, a further increase ,in the flow of air into thegaseous mixture around the valve 44. Also, it will be seen that the presence of the dash-pot 50 enables the apparatus to work regularly and without any sudden changes in the mixture controlled thereby. The operating condi-' tions of the apparatus may be adjusted by the adjustment of the valve seat 39 and also by the adjustment of the dash-pot 50. The adjustment of the valve seat 39 downwardly will result in producing a mixture that is richer through the entire range of operation and the adjustment of the dash-pot downwardly will result in a slower change of the apparatus to adapt itself to differences in the operation of the engine. It will, furtheremore, be understood that the shape and size of the valve 43 may be changed to suit the metering characteristic required for any particular engine.' Again it will be understood that by locating the nozzle 25 in the manner indicated in Figure '3 there will always be a quantity of liquid fuel within the sleeve 23 thus insuring the presence of a priming charge which will aid in the starting of the engine.

The operation and modification of my i11- vention shown in Figure 4 is the same as the operation of the apparatus as previously set forth except that in this instance the adjustment of the corrugated rod 54 on the dash of the automobile will enable the richness of the mixture to be adjusted as desired. This will be especially useful in the starting of the engine.

Under some conditions the pressure of the inert gases issuing from the exhaust may be utilized to control the position of valve 44 instead ofthe incoming airto feed the fuel in proper quantity; in such case the heat of the exhaust gases will also assist in supplying the fuel in vaporized form.

terraces mixture, a conduit having an initial air inlet port located distantly from the engine and leading from said inlet for discharge to the engine, a fuel atomizer comprising an initial part of said conduit, and a fuel duct discharging thereinto, distantly from the engine posterior to said distant air inlet, said conduit having a secondary inlet intermediate the atomizer and the engine, and means, relatively proximate'to the engine for cont-rolling the atomization of fuel varyingly according to the running conditions of the engine, said means comprising a device consisting of two valves connected for simultaneous movement and seating,-the first at said intial inlet port and the second at said intermediate port.

2. In the construction defined in claim I, the second mentioned valve being normally seated so as to be moved in opening direction by the inward movement of air past it into the conduit, and a throttle valve positioned for controlling said air movement; whereby the simultaneous admission of air to the atomizer and to the conduit is throttlecontrolled.

3. In the construction defined in claim I, the second mentioned valve being normally yieldingly seated and adapted to be opened by inflow of air, and a dash pot connected with said valve for damping its opening movement.

4. In the construction defined in claim 1, the fuel mixture conduit from the source of -.fuel to the engine comprising a constantlevel fuel supply chamber, the automizer having its air inlet positioned for deriving air for atomizing the fuel from said constant-level chamber.

5. In a structure for the purpose indicated in combination with a source of fuel and a fuel mixture conduit, the source of fuel comprising a constant-level supply chamber located distantly from the engine; a fuel atomizer located proximate to the constantlevel chamber and connected for deriving its air supply for atomization from said constant-level chamber, the conduit having an air inlet between the atomizer and the engine, and means relatively proximate to to be moved in opening direction by the inward air movement past it, and a throttle valve positioned for controlling said airmovement; whereby the air supply to the atomizer derived through the constant-level chamber is throttle-controlled.

6. In a structure for the purpose indicated, in combination with a source of fuel, an atomizing device for forming an initial fuel mixture located distantly from the engine having an initial air inlet and connected for deriving'fuel supply from said fuel source; a fuel mixture conduit from the atomizing device leading for delivery of fuel mixture to the engine, said conduit having an auxiliary atmospheric air inlet relatively proximate to the engine; a conduit for supplemental air supply to the vaporizing device; valves for controlling said auxiliary air inlet and said supplemental air inlet, means connecting said valves for simultaneous operation, and means for controlling their operation according to the action of the engine for developing suction at the COl111G(- tion of the fuel mixture conduit therewith.

T. In a structure for the purpose indicated, in combination with a source of fuel, an atomizingdevice for forming aninitial fuel mixture located distantly from the engine having an initial air inlet and connected for deriving fuel supply from said fuel source: a fuel mixture conduit from the atomizing device leading for delivery of fuel mixture to the engine, said conduit having an anxiliary atmospheric air inlet relatively proximate to the engine; a conduit for supplemental air supply to thevaporizing device; valves for controlling said auxiliary air inlet and said supplemental air inlet, means connecting said valves for simultaneous operation, a dash pot connected with said valve operating connections for controlling the operation of said valves.

8. In a structure for the purpose indicated in combination with a fuel mixture conduit adapted for connection with the intake manifold of the engine to be'served, a fuel atomizer for producing an initial fuel mixture comprising connection for discharging the fuel element of the fuel mixture into said conduit, the conduit having an air inlet situated for admitting additional air to the initial fuel mixture at a point intermediate the atomizer and the discharge of the conduit at the intake manifold means for controlling the initial fuel mixture produced by the atomizer varyingly according to the running conditions of the engine comprising separate valve meansfor controlling the admission of air anterior to the atomizer and the admission of the additional air to the conduit intermediate the atomizer and the engine, and means for simultaneously operating said separate valve means.

In testimony that I claim the foregoing, I have hereunto'set my hand this 12th day of July, 1923.

. EDWARD A. ROCKWELL. 

